Fixed Bed Column Study for Removal of Textile Effluent Acid Orange 7 by NaOH Treated Eggshells and Amberlite FPA-98 as Efficient Adsorbents Using Response Surface Methodology.
In this study, we investigated the adsorption of Methylene blue (MB) dye on prepared activated carbons from eggshells treated with NaOH (TES) and eggshells Without Treatment (NTES) as a new and potential biosorbent. Biosorption capacities and rates of different kinds of treated bioadsorbent for Removal of MB dye from aqueous solutions were compared under laboratory conditions as a function of initial dye concentration, temperature and pH . The extent of dye removal increased with increasing in the initial concentration of the dye ,increased with increase in contact time and the initial pH of the solution and also decreased with increasing in temperature of the adsorbent. Adsorption data were modeled using the Freundlich and Langmuir to fit experimental equilibrium data at different solution temperatures and the isotherm parameters were calculated in order to describe the biosorption process; Langmuir model was found suitable for describing the biosorption of the dye by all the bioadsorbent. Among the two adsorbents , TES exhibited the highest dye uptake capacity (Q0 =200 mg/g) at 20°C. A Comparison of different kinetic models parameters was evaluated for the pseudo-first-order and the pseudo-second-order model on the removal of MB. The results indicated that the dye uptake process followed the pseudo-second-order kinetics for each dye–adsorbent system. The thermodynamic parameters were evaluated; The negative values of ΔH° and ΔG° indicated respectively that the adsorption of MB onto TES and NTES was exothermic and spontaneous process, concerning ΔS° which is also negative, it have showed that disorder in the interface system decreases during the adsorption process. In summary, the results have established good potentiality for the TES and NTES particles to be employed as a low cost sorbent for the removal of colour and dyes from wastewater.
